Optical character recognition, usually abbreviated to OCR, is the
mechanical or electronic translation of scanned images of handwritten,
typewritten or printed text into machine-encoded text. It is widely used
to convert books and documents into electronic files, to computerize a
record-keeping system in an office, or to publish the text on a website.
OCR makes it possible to edit the text, search for a word or phrase, store
it more compactly, display or print a copy free of scanning artifacts, and
apply techniques such as machine translation, text-to-speech and text
mining to it. OCR is a field of research in pattern recognition, artificial
intelligence and computer vision.
OCR systems require calibration to read a specific font; early versions
needed to be programmed with images of each character, and worked
on one font at a time. "Intelligent" systems with a high degree of
recognition accuracy for most fonts are now common. Some systems are
capable of reproducing formatted output that closely approximates the
original scanned page including images, columns and other non-textual
In 1929 Gustav Tauschek obtained a patent on OCR in Germany, followed
by Handel who obtained a US patent on OCR in USA in 1933 (U.S. Patent
1,915,993). In 1935 Tauschek was also granted a US patent on his
method (U.S. Patent 2,026,329). Tauschek's machine was a mechanical
device that used templates and a photodetector.
RCA engineers in 1949 worked on the first primitive computer-type OCR
to help blind people for the US Veterans Administration, but instead of
converting the printed characters to machine language, their device
converted it to machine language and then spoke the letters. It proved
far too expensive and was not pursued after testing.
In 1950, David H. Shepard, a cryptanalyst at the Armed Forces Security
Agency in the United States, addressed the problem of converting
printed messages into machine language for computer processing and
built a machine to do this, reported in the Washington Daily News on 27
April 1951 and in the New York Times on 26 December 1953 after his U.S.
Patent 2,663,758 was issued. Shepard then founded Intelligent Machines
Research Corporation (IMR), which went on to deliver the world's first
several OCR systems used in commercial operation.
The first commercial system was installed at the Reader's Digest in 1955.
The second system was sold to the Standard Oil Company for reading
credit card imprints for billing purposes. Other systems sold by IMR
during the late 1950s included a bill stub reader to the Ohio Bell
Telephone Company and a page scanner to the United States Air Force
for reading and transmitting by teletype typewritten messages. IBM and
others were later licensed on Shepard's OCR patents.
In about 1965 Reader's Digest and RCA collaborated to build an OCR
Document reader designed to digitise the serial numbers on Reader's
Digest coupons returned from advertisements. The font used on the
documents were printed by an RCA Drum printer using the OCR-A font.
The reader was connected directly to an RCA 301 computer (one of the
first solid state computers). This reader was followed by a specialised
document reader installed at TWA where the reader processed Airline
Ticket stock. The readers processed document at a rate of 1,500
documents per minute, and checked each document, rejecting those it
was not able to process correctly. The product became part of the RCA
product line as a reader designed to process "Turn around Documents"
such as those Utility and insurance bills returned with payments.
The United States Postal Service has been using OCR machines to sort
mail since 1965 based on technology devised primarily by the prolific
inventor Jacob Rabinow. The first use of OCR in Europe was by the British
General Post Office (GPO). In 1965 it began planning an entire banking
system, the National Giro, using OCR technology, a process that
revolutionized bill payment systems in the UK. Canada Post has been
using OCR systems since 1971. OCR systems read the
name and address of the addressee at the first mechanised sorting
center, and print a routing bar code on the envelope based on the postal
code. To avoid confusion with the human-readable address field which
can be located anywhere on the letter, special ink (orange in visible light)
is used that is clearly visible under ultraviolet light. Envelopes may then
be processed with equipment based on simple barcode readers.
In 1974 Ray Kurzweil started the company Kurzweil Computer Products,
Inc. and led development of the first omni-font optical character
recognition system — a computer program capable of recognizing text
printed in any normal font. He decided that the best application of this
technology would be to create a reading machine for the blind, which
would allow blind people to have a computer read text to them out loud.
This device required the invention of two enabling technologies — the
CCD flatbed scanner and the text-to-speech synthesizer. On January 13,
1976 the successful finished product was unveiled during a
widely-reported news conference headed by Kurzweil and the leaders of
the National Federation of the Blind.
In 1978 Kurzweil Computer Products began selling a commercial version
of the optical character recognition computer program. LexisNexis was
one of the first customers, and bought the program to upload paper legal
and news documents onto its nascent online databases. Two years later,
Kurzweil sold his company to Xerox, which had an interest in further
commercializing paper-to-computer text conversion. Kurzweil Computer
Products became a subsidiary of Xerox known as Scansoft, now Nuance